Communication method and system that uses low latency/low data bandwidth and high latency/high data bandwidth pathways

ABSTRACT

A communication system uses multiple communications links, preferably links that use different communications media. The multiple communications links may include a high latency/high bandwidth link using a fiber-optic cable configured to carry large volumes of data but having a high latency. The communications links may also include a low latency/low bandwidth link implemented using skywave propagation of radio waves and configured to carry smaller volumes of data with a lower latency across a substantial portion of the earth&#39;s surface. The two communications links may be used together to coordinate various activities such as the buying and selling of financial instruments.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/946,110, filed Apr. 5, 2018, which is hereby incorporated byreference. U.S. patent application Ser. No. 15/946,110, filed Apr. 5,2018, is a continuation of U.S. patent application Ser. No. 15/296,528,filed Oct. 18, 2016, which are hereby incorporated by reference. U.S.patent application Ser. No. 15/296,528, filed Oct. 18, 2016, is acontinuation of U.S. patent application Ser. No. 14/843,391, filed Sep.2, 2015, which are hereby incorporated by reference. U.S. patentapplication Ser. No. 15/296,528, filed Oct. 18, 2016, is also acontinuation of International Patent Application NumberPCT/US2015/064474, filed Dec. 8, 2015, which are hereby incorporated byreference. International Patent Application Number PCT/US2015/064474,filed Dec. 8, 2015, is a continuation of U.S. patent application Ser.No. 14/566,851, filed Dec. 11, 2014, which are hereby incorporated byreference. International patent Application Number PCT/US2015/064474,filed Dec. 8, 2015, is also a continuation of U.S. patent applicationSer. No. 14/843,391, filed Sep. 2, 2016, which are hereby incorporatedby reference. U.S. patent application Ser. No. 14/843,391, filed Sep. 2,2016, is a continuation of U.S. patent application Ser. No. 14/566,851,filed Dec. 11, 2014, which are hereby incorporated by reference.

BACKGROUND

Recent technological improvements have dramatically improved the abilityto communicate across vast distances. Extensive fiber optic andsatellite networks now allow remote parts of the world to communicatewith one another. However, by spanning across these great distances,such as across the Atlantic or Pacific Oceans, fiber optic cables canincur a round-trip latency or time lag of about 60 msec or more.Satellite communications can experience even greater lag times. In manycases, this high latency cannot be overcome because it is inherent inthe communications medium and equipment. For example, light may traversean optical fiber 30-40% more slowly than a radio wave traveling the samedistance through free space. Fiber optic networks typically requiremultiple repeaters that further increase latency. While generally notproblematic in a number of circumstances, this high latency can causeunacceptable delays in the execution of time sensitive activities,especially time sensitive activities that require complex logic and/orare dependent on conditions that rapidly change. These latency issuescan for example create problems for a whole host of activities, such asin the operation and/or synchronization of distributed computer systems,scientific experiments with geographically large sensor arrays, andtelemedicine/diagnostic activities, to name just a few. In oneparticular example, orders to buy and sell securities or other financialinstruments in world markets typically rely on communications links thatcarry data and instructions over systems using fiber optic lines,coaxial cables, or microwave communication links. Any delays inexecuting an order, such as caused by the high latency across fiberoptic lines, can lead to significant financial losses.

SUMMARY

A unique communication system and method has been developed to addressthe above-mentioned latency issues as well as other issues. In thecommunication system, command data is transmitted so as to be receivedat a receiving station before (or at the same time) triggering data isreceived. The command data includes one or more directives,instructions, algorithms, and/or rules for controlling a machine, suchas a computer and/or mechanical device, to take one or more actions. Forexample, the command data in one form includes a program for buyingand/or selling particular options or stocks at certain price levels,ranges, and/or based on other conditions. Command data is typically (butnot in all circumstances) larger in size than the triggering data suchthat the command data takes longer than the triggering data to transmitover communication links having the same data bandwidth. The triggeringdata includes information identifying one or more commands in thecommand data to execute. For example, the triggering data can identifyone or more particular options in the command data that identifies theparticular stock (or multiple stocks) to purchase at a particular price(or prices). In one example, the command data is transmitted over acommunication link that has high bandwidth and high latency, such asover a fiber optic cable, and the triggering data is transmitted over acommunication link that has low bandwidth and low latency, such asthrough sky-wave propagation by refracting and/or scattering radio wavesfrom the ionosphere. The relatively small-sized triggering data is thenable to be more quickly received at a receiving station than if thetriggering data was transmitted over the high bandwidth and high latencycommunication link provided by fiber optic cable. This communicationsystem and method dramatically reduces the time to execute complextime-sensitive actions, such as financial transactions, over largedistances at remote locations. In one form, this technique is used toremotely perform actions past the radio horizon, such as fortransatlantic communications. This technique can be adapted for one-waytype communications or even two-way type communications.

This unique communication system and method in one example uses multiplecommunications links. In one form, the communication links use differentcommunications media. Such a system might be used, for example, totransmit a large collection of preprogrammed commands or rules over ahigh latency/high bandwidth link in advance of a triggering event whichmay be a market event, news report, a predetermined date and time, andthe like. This set of rules or preprogrammed actions may be sent as asoftware update to an executable program, or as a firmware upgrade for aField Programmable Gate Array (FPGA). When a triggering event occurs,triggering data can be sent over a low latency/low bandwidth link alone,or over both links, causing the preprogrammed commands to be executed asplanned.

In one example of the system, the low latency/low bandwidthcommunications link uses radio waves to transmit data in concert withthe higher latency/high bandwidth communications link which may be apacket switched network operating over fiber optic cables. Such acombination may include various combinations with widely varyingdifferentials between the high and low latency links. The low latencylink may use high frequency (HF) radio waves to transmit over apropagation path between North America and Europe. Radio waves maytransmit, for example, with a one-way latency of 20 to 25 ms or less (40to 50 ms round trip). A higher latency link may carry data over adifferent propagation path, or perhaps through a different mediumbetween the same two continents that, for example, may have a latency ofabout 30 ms or more one-way, or 60 ms or more both ways.

The system may also constantly monitor and use different HF bands tomaintain the highest available signal strength between remote locationsdepending on solar and atmospheric conditions. This monitoring mayinclude accessing third-party data, analyzing results obtained byexperimentation, and/or using software modeling. These conditions can beparticularly important in the low latency link which may use skywavepropagation to relay HF transmissions over long distances. This skywavepropagation may be augmented by repeater stations on the ground orpossibly in the air.

In another aspect, overall security of the system may be enhanced bysending a continual stream of actions and/or triggering messages overthe separate communications links to confuse malicious third parties anddiscourage attempts to intercept and decipher future transmissions.These messages may be very short, or intermingled with various othertransmissions which may go on continuously, or for only short periods oftime on a predetermined schedule. In a related aspect, security may beenhanced by sending short messages over skywave propagation on one ormore frequencies, or by sending small parts of a message on severalfrequencies at the same time. Various additional techniques may also beemployed to enhance security such as encryption, two-way hashing, andthe like, which may incur additional latency in both links.

So as to aid in appreciating the unique features of this communicationsystem and method, the communication system and method will be describedwith reference to executing trades of stocks, bonds, futures, or otherfinancial instruments, but it should be recognized that this system andmethod can be used in a large number of other fields where latency is aconcern, such as for distributed computing, scientific analysis,telemedicine, military operations, etc. Further forms, objects,features, aspects, benefits, advantages, and embodiments of the presentinvention will become apparent from a detailed description and drawingsprovided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a system for transmitting data overseparate communication links, one of which uses skywave propagation.

FIG. 2 is a schematic diagram further illustrating the skywavepropagation of FIG. 1

FIG. 3 is a schematic diagram illustrating the use of ground-basedrepeaters in the skywave propagation of FIG. 1.

FIG. 4 is a student schematic diagram illustrating the use of airbornerepeaters in the skywave propagation of FIG. 1.

FIG. 5 is a schematic diagram illustrating additional layers of theatmosphere including the ionized layer shown in FIG. 1.

FIG. 6 is a schematic diagram illustrating various ionized layers of theatmosphere shown in FIG. 5.

FIG. 7 is a schematic diagram illustrating additional details of skywavepropagation generally illustrated in FIGS. 1-6.

FIG. 8 is a schematic diagram illustrating additional detail for thecommunication nodes of FIG. 1.

FIG. 9 is a schematic diagram illustrating additional detail for the RFcommunication interface in FIG. 8.

FIGS. 10-13 are timing diagrams illustrating the coordinated use ofmultiple communication links like those illustrated in FIGS. 1-9.

FIG. 14 is a flowchart generally illustrating actions taken by thesystem of FIGS. 1-13.

FIG. 15-18 are flowcharts illustrating additional detail for actionsillustrated in FIG. 14.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates. One embodiment of the invention is shown in great detail,although it will be apparent to those skilled in the relevant art thatsome features that are not relevant to the present invention may not beshown for the sake of clarity.

FIG. 1 illustrates at 100 one example of a system configured to transferdata via a low latency, low bandwidth communication link 104, andseparate data via a high latency, high bandwidth communication link 108.Communication links 104 and 108 provide separate connections between afirst communication node 112 and a second communication node 116. Lowlatency connection 104 may be configured to transmit data usingelectromagnetic waves 124 passing through free space via skywavepropagation. Electromagnetic waves 124 may be generated by a transmitterin first communication node 112, passed along a transmission line 136 toan antenna 128. Waves 124 may be radiated by antenna 128 encountering anionized portion of the atmosphere 120. This radiated electromagneticenergy may then be refracted by the ionized portion of the atmosphere120 causing waves 124 to redirect toward earth. Waves 124 may bereceived by a receiving antenna 132 coupled to second communicationsnode 116 by transmission line 140. As illustrated in FIG. 1, atransmitting communication node may use skywave propagation to transmitelectromagnetic energy long distances across the earth surface withoutthe need of one or more transmission lines to carry the electromagneticenergy.

Data may also be transmitted between communications nodes 112 and 116using a high latency communication link 108. As illustrated in FIG. 1,high latency communication link 108 may be implemented using atransmission line 144 passing through the earth, which may includepassing under or through an ocean or other body of water. As shown inFIG. 1, the high latency communication link may include repeaters 152.FIG. 1 illustrates four repeaters 152 along transmission line 144although any suitable number of repeaters 152 may be used. Transmissionline 144 may also have no repeaters at all. Although FIG. 1 illustratescommunication link 104 transmitting information from first communicationnode 112 to second communication node 116, the data transmitted may passalong communication links 104, 108 in the both directions.

The configuration shown in FIG. 1 is further illustrated in FIG. 2 wherefirst communication node 112 and second communication node 116 aregeographically remote from one another separated by a substantialportion of the surface of the earth (156). This portion of the earth'ssurface may include one or more continents, oceans, mountain ranges, orother geographic areas. For example, the distance spanned in FIGS. 1-7may cover a single continent, multiple continents, an ocean, and thelike. In one example, node 112 is in Chicago, Ill. in the United Statesof America, and node 116 is in London, England, in the United Kingdom.In another example, node 112 is in New York City, N.Y., and node 116 isin Los Angeles, Calif., both cities being in North America. Any suitablecombination of distance, communication nodes, and communications linksis envisioned that can provide satisfactory latency and bandwidth.

FIG. 2 illustrates that skywave propagation allows electromagneticenergy to traverse long distances. Using skywave propagation, lowlatency communication link 104 transmits electromagnetic waves 124 intoa portion of the atmosphere 120 that is sufficiently ionized to refractelectromagnetic waves 124 toward the earth. The waves may then bereflected by the surface of the earth and returned to the ionizedportion of the upper atmosphere 120 where they may be refracted towardearth again. Thus electromagnetic energy may “skip” repeatedly allowingthe low latency, low bandwidth signals 124 to cover distancessubstantially greater than those which may be covered by non-skywavepropagation.

Another example of the system illustrated in FIG. 1 appears in FIG. 3where the skywave propagation discussed with respect to FIGS. 1 and 2may be enhanced using repeaters 302 and 306. In this example, firstrepeater 302 may receive the low latency communication signals emanatingfrom antenna 128. The signals may be refracted by the ionized region 120and returned to earth where they may be received by repeater 302 andretransmitted via skywave propagation. The refracted signal may bereceived by repeater 306 and retransmitted using skywave propagation tosecond communications node 116 via antenna 132. Although two repeatingstations are illustrated in FIG. 3, any suitable number, configuration,or positioning of ground repeating stations 302 is considered.Increasing the number of repeaters 302, 306 may provide for theopportunity to transmit low latency signals over greater distances in awider array of atmospheric missions, however, the physical limitationsof the repeater circuitry that receives and retransmits the signal mayadd additional latency to low latency communication link 104.

FIG. 4 illustrates another example of the system illustrated in FIG. 1where one or more repeaters along the first communications link areairborne, such as in an aircraft, dirigible, balloon, or other device410 configured to maintain the repeater aloft in the atmosphere. In thisexample, signals transmitted from first communications node 112 viaantenna 128 may be received by an airborne repeater 414 either as lineof sight communication 402, or by skywave propagation as describedherein elsewhere. The signals may be received by airborne repeater 414and retransmitted as line of sight communication 406, or by skywavepropagation to the second communications node 116 along the low latencylink 104.

Additional details regarding skywave propagation are illustrated inFIGS. 5-7. The relation to the system disclosed and various layers ofthe upper atmosphere is illustrated in FIG. 5. For purposes of radiotransmission, the layers of the upper atmosphere may be divided as showninto successively higher layers such as the troposphere 504, thestratosphere 508, and the ionosphere 512.

The ionosphere is named as such because it includes a high concentrationof ionized particles. The density of these particles in the ionospherefurthest from earth is very low and becomes progressively higher in theareas of the ionosphere closer to earth. The upper region of theionosphere is energized by powerful electromagnetic radiation from thesun which includes high-energy ultraviolet radiation. This solarradiation causes ionization of the air into free electrons, positiveions, and negative ions. Even though the density of the air molecules inthe upper ionosphere is low, the radiation particles from space are ofsuch high energy that they cause extensive ionization of the relativelyfew air molecules that are present. The ionization extends down throughthe ionosphere with diminishing intensity as air becomes denser with thehighest degree of ionization thus occurring at the upper extremities ofthe ionosphere, while the lowest degree occurs in the lower portion ofthe ionosphere.

These differences in ionization between the upper and lower extremitiesof the ionosphere 512 are further illustrated in FIG. 6. The ionosphereis illustrated in FIG. 6 with three layers designated, respectively,from lowest level to highest level as D layer 608, E layer 612, and Flayer 604. The F layer 604 may be further divided into two layersdesignated F1 (the higher layer) at 616 and F2 (the lower layer) at 620.The presence or absence of layers 616 and 620 in the ionosphere andtheir height above the earth vary with the position of the sun. At highnoon, radiation from the sun 624 passing into the ionosphere isgreatest, tapering off at sunset and at a minimum at night. When theradiation is removed, many of the ions recombine causing the D layer 608and the E layer 612 to disappear, and further causing the F1 and F2layers 616, 620 to recombine into a single F layer 604 during the night.Since the position of the sun varies with respect to a given point onearth, the exact characteristics of layers 608, 612, 616, and 620 ofionosphere 512 can be extremely difficult to predict but may bedetermined by experimentation.

The ability for a radio wave to reach a remote location using skywavepropagation depends on various factors such as ion density in layers608-620 (when they are present), the frequency of the transmittedelectromagnetic energy, and the angle of transmission. For example, ifthe frequency of a radio wave is gradually increased, a point will bereached where the wave cannot be refracted by D layer 608 which is theleast ionized layer of ionosphere 512. The wave may continue through theD layer 608 and into the E layer 612 where its frequency may still betoo great to refract the singles passing through this layer as well. Thewaves 124 may continue to the F2 layer 620 and possibly into the F1layer 616 as well before they are bent toward earth. In some cases, thefrequency may be above a critical frequency making it impossible for anyrefraction to occur causing the electromagnetic energy to be radiatedout of the earth's atmosphere (708).

Thus, above a certain frequency, electromagnetic energy transmittedvertically continues into space and is not refracted by ionosphere 512.However, some waves below the critical frequency may be refracted if theangle of propagation 704 is lowered from the vertical. Lowering theangle of propagation 704 also allows electromagnetic waves 124transmitted by antenna 128 to be refracted toward Earth's surface withina skip zone 720 making it possible to traverse a skip distance 724 andreach a remote antenna 132. Thus the opportunity for successful skywavepropagation over a certain skip distance 724 is further dependent on theangle of transmission as well as the frequency, and therefore themaximum usable frequency varies with the condition of the ionosphere,desired skip distance 724, propagation angle 704. FIG. 7 alsoillustrates that non-skywave propagation such as groundwave signalsand/or line of sight signals 716 are unlikely to traverse skip distance724.

FIG. 8 illustrates one example of additional aspects of a communicationnode 800 which is like communication nodes 112 and 116. Communicationnode 800 can include a processor 804 for controlling various aspects ofcommunication node 800. The processor may be coupled to a memory 816useful for storing rules or command data 820. Devices for accepting userinput and providing output (I/O) to a user (824) may also be included.These devices may include a keyboard or keypad, a mouse, a display suchas a flat panel monitor and the like, a printer, plotter, or 3D printer,a camera, or a microphone. Any suitable devices for user I/O may beincluded. Node 800 may also include a network interface 832 responsiveto the processor 804 and coupled to a communication network 836. Asecurity module 828 may be included as well and may be used to reduce oreliminate the opportunity for third-parties to intercept, jam, or changedata as it passes between communications nodes 800. In one example,communication node 800 is implemented as a computer executing softwareto control the interaction of the various aspects of node 800.

Network interface 836 may be configured to send and receive data such ascommand data 820, or triggering data which may be passed from atriggering system 840. Communication network 836 may be coupled to anetwork such as the internet and configured to send and receive datawithout the use of skywave propagation. For example, communicationnetwork 836 may transmit and receive data over optical fibers or othertransmission lines running along the earth similar to transmission lines144 illustrated in previous figures.

Node 800 may include a second network interface 808 responsive toprocessor 804 and coupled to a radio-frequency communication interface812. This second network interface 808 may be used to transfer data suchas command data 820 or triggering data passed from triggering system840. Network interface 808 may be coupled to an antenna like antenna 128which may include multiple antennas or antenna elements. Theradio-frequency communication interface 808 may be configured to sendand receive data such as triggering data using electromagnetic wavestransmitted and/or received via antenna 128. As discussed above, antenna128 may be configured to send and receive the electromagnetic waves viaskywave propagation.

Node 800 may include additional aspects illustrated in FIG. 9.Radio-frequency communication interface 812 may include a transmitter904 configured to transmit electromagnetic energy using antenna 128.Receiver 908 may optionally be included as well and configured toreceive electromagnetic waves from antenna 128. Transmitter 904 andreceiver 908 may also be coupled to a modem 912 configured to modulatesignals received by interface 812 to encode information or data from adigital stream for transmission by transmitter 904. Modem 912 may alsobe configured to demodulate signals received by receiver 908 fromantenna 128 to decode the transmitted signal into a digital data streamusable by processor 804 or that may be stored in memory 816.

FIGS. 10 through 13 illustrate examples of the disclosed system inoperation illustrating how various networks can be used either alone, orin concert, to transmit command and triggering data corresponding withvarious events. FIGS. 10-13 illustrate the use of two separatecommunications links labeled “A” and “B.” These links may use anysuitable communication link separately or in tandem as shown. Forexample, communication link A may be a low latency link likecommunication link 104, and communication link B may be a high latencylink like communication link 108. In another example, both links A and Bmay be low latency communication links. In yet another example, bothcommunication links may be high latency communication links. In anotheraspect, any combination of data bandwidth may be used for links A and B.For example, link A may be a low latency link with either high or lowdata bandwidth, and link B may be a high latency link with either highor low data bandwidth.

More specifically, in one example, link A is a low latency/low bandwidthcommunication link carrying triggering signals and is implemented asdiscussed herein using HF radio waves propagated via skywavepropagation. In this example, link B is a high latency/high bandwidthcommunication link carrying command data and is implemented as discussedherein using fiber-optic cables, coaxial cables, or other transmissionlines.

FIG. 10 illustrates such a system in operation illustrating links A andB passing data corresponding to events 1020, 1024, and 1028 as timepasses. In FIG. 10, link B is illustrated as having a higher databandwidth and higher latency than low latency link A. High latency linkB is utilized to transfer command data over a period of time prior tocorresponding successive events. Before event 1020, command data 1016may be transferred over high latency link B taking a relatively shortamount of time to transfer a large volume of data due to the higher databandwidth of link B. At about the time event 1020 occurs, a triggeringsignal 1012 may be transmitted over low latency link A. The triggeringsignal 1012 may include an identifier identifying one or more commandsto be executed by a processor such as processor 804.

This process may be repeated multiple times were data 1017 correspondingwith a subsequent event 1024 may be transferred over high latency link Bahead of event 1024. Trigger signal 1013 may then be sent over lowlatency link A using skywave propagation in response to event 1024resulting in the execution of various instructions or rules in aprocessor of the receiving communications node. Event 1028 may cause thesystem to send trigger 1024 which may select commands sent along withdata 1018 in advance. Thus FIG. 10 illustrates a successive transfers ofdata 1016, 1017, and 1018 over high latency link B from onecommunications node to a remote communications node. As events 1020,1024, and 1028 occur over time, triggering signals 1012, 1013, 1014 maybe triggered using low latency link A to quickly transfer informationconfigured to trigger the remote receiving communications node to act oncommands or other aspects of data 1016, 1017, and 1018 sent before thecorresponding events take place.

Other configurations and uses of links A and B are envisioned as well.In another example, link A is a low latency/low bandwidth communicationlink carrying both command data and triggering signals and isimplemented as discussed herein using HF radio waves propagated viaskywave propagation. In this example, link B is a high latency/highbandwidth communication link carrying command data and triggering data,and is implemented as discussed herein using fiber-optic cables, coaxialcables, or other transmission lines.

The operation of this example of the disclosed system is illustrated inFIG. 11. In FIG. 11, data 1116, 1117, 1118 are transmitted using bothlow latency link A and high latency link B. Triggering signals 1112,1113, and 1114 may also be transmitted over both link A and link B asillustrated in response to events 1120, 1124, and 1128. In thisconfiguration, the high and low latency links A and B respectivelyprovide redundancy so that if triggering or command data fails to betransmitted or received, (such as signal 1112 on link A or data 1118 andtriggering signal 1114 on link B) the data may still be passed to theremote communications node through another communications link. Signals1112 or 1114 may not be received or sent for any number of reasons suchas equipment failures, changes in atmospheric conditions, severed ordamaged fiber-optic cables, damage to antennas or antenna arrays, andthe like.

As illustrated in FIG. 11, link A may require additional time totransfer data 1116, 1117, 1118 where low latency link A has a lower databandwidth then high latency link B. In other examples, these situationsmay be reversed where high latency link B takes longer to transfer datathan low latency link A, or both links A and B may take about the sameamount of time. FIG. 11 illustrates that, for example, data 1116 maytake longer to transmit on low latency/low bandwidth link A then on highlatency/high bandwidth link B.

FIG. 12 illustrates another example of a low latency/low bandwidth linkA transferring commands and triggering data corresponding to command andtriggering data passed over a high latency/high bandwidth link B. Inthis example, data 1216 is transferred over link B ahead of an event1220. Triggering signal 1212 is passed over link A in response to event1220 to activate or execute commands, rule comparisons or otherinstructions corresponding with data 1216. In this example, high latencylink B transfers data 1216 as part of a steady stream of encoded datatransmissions 1240. Encoded data 1240 may include hashed, encrypted, orotherwise obfuscated data transmissions to mask data 1216 reducing oreliminating the opportunity for unauthorized access. This data encodingmay use any suitable technique such as public or private key encryption,one or 2-way hashing, and the like. In this example, encoded data stream1240 is transferred continuously over high latency link B and includesdata 1216, 1217, and 1218, along with triggering signals 1212, 1213, and1214. FIG. 12 also illustrates that the system may be configured totransmit triggering signals without including them in encoded data 1240(1212, 1213), and may optionally begin sending the encoded stream 1240over low latency link A along with a later set of triggering data 1214.By sending a continuous stream of data that may or may not includecommand or triggering data, unauthorized access to commands encoded intransmissions 1240 may be reduced or eliminated altogether in advance ofevents 1220, 1224, and 1228.

Transmissions sent on low latency link A may also be encoded to reduceor eliminate the opportunity for unauthorized access and may or may notbe sent in tandem with encoded data 1240. As illustrated in FIG. 12,triggering signal 1212 may be sent without being part of a continuousstream of encoded data while in another example, a similar triggeringsignal 1214 may be sent as part of encoded data 1240. With low latencylink A, similar encoding techniques may be used for the data such aspublic or private key encryption, one-way or two-way hashing, or othersuitable means of obscuring triggering data 1214. By sending triggeringdata as part of a continuous encoded data stream, unauthorized accessmay be reduced or eliminated as triggering signals may be time sensitivemaking it prohibitively expensive to determine the contents of thetriggering signal before it is either used or its usefulness expires.

Another example of the disclosed system in operation is illustrated inFIG. 13 where triggering signals 1312, 1313, 1314 may correspond withlow latency link A ceasing to send a carrier signal or data stream 1350.The communication nodes may be configured to receive carrier 1350 andmay be triggered to accept a triggering signal 1312, 1313, or 1314 whencarrier 1350 ceases to be sent ahead of sending the triggering signal.Carrier signal 1350 may include a continuous digital or analog signalsent by skywave propagation, or by any other suitable means. The signalmay include a continuous analog signal at a single frequency, a signalthat varies continuously with time, or other suitable signal. Carriersignal 1350 may also include digital data transmissions including, forexample, a repeated series of datagrams containing information thatremains the same, or changes in a predictable fashion with time.

A dropout or change in the carrier signal, for example at 1315, mayindicate a triggering signal to the receiving communications node, orthat a triggering signal is about to be sent. This example may becharacterized as a communications node configured to trigger a responsebased on data 1316, 1317, 1318 on a “signal low” condition such as whenthe carrier 1350 stops transmitting at 1315 just ahead of thetransmission of triggering signal 1312, 1313, or 1314. High latency linkB may be configured similarly. The use of a carrier 1350 may be used inconjunction with any other methods illustrated in FIGS. 10-13, or anycombination thereof, to respond to any events discussed above.

In any of the examples disclosed herein (such as in FIGS. 10-13),overall security of the system may be enhanced by sending a continualstream of actions and/or triggering messages over the separatecommunications links to confuse malicious third parties and discourageattempts to intercept and decipher future transmissions. The samemessages may be sent over multiple links simultaneously, over separatetransmitters and receivers with different propagation paths, or in anycombination thereof. These messages may be very short, or intermingledwith other transmissions and may be sent continuously, or for only shortperiods of time on a predetermined schedule. In a related aspect,security may be enhanced by sending short messages over skywavepropagation on one or more frequencies, or by sending small parts of amessage on several frequencies at the same time. Various additionaltechniques may also be employed to enhance security such as encryption,two-way hashing, and the like, which may incur additional latency inboth links.

No association in the time required to pass data of the same or similarsize across both links should be interpreted from FIGS. 10-13. AlthoughFIGS. 10-13 may illustrate a relationship between the length of timerequired for high latency/high bandwidth link B to transfer data versuslow latency/low bandwidth link A, FIGS. 10-13 is illustrative ratherthan restrictive Link A make take more or less time to send data of thesame size as Link B and vice versa.

In any of the communication links illustrated in FIGS. 10-13, skywavepropagation may be used to transmit data. For example, both links A andB may be low latency links using skywave propagation as discussedherein. In this example, low latency links A and B may both beconfigured for high or low data bandwidth. In another example, bothlinks A and B may be high latency links using propagation techniquesother than skywave propagation such as electromagnetic waves passedthrough fiber-optic cables, copper wire, and the like to name a fewnonlimiting examples. High latency links A and B may be configured forhigh or low data bandwidth.

Illustrated at 1400 in FIG. 14 is a general flow of actions that may betaken by a system implementing the features discussed above (e.g. thesystem illustrated in FIG. 1). Commands or command data may be initiallysent at 1404 by a transmitting communications node such as node 112 ornode 800 configured to transmit command data. The system may wait for atriggering event (1408) and send triggering data at 1412 when atriggering event occurs. A receiving communications node (e.g. likenodes 116 or 800) may then execute commands (1416) included in thecommand data accordingly.

Illustrated in FIG. 15 is additional detail regarding the actions thatmay be taken in sending command data (1404). At 1504, command data maybe received or created. The data may be received from a transmittingthird-party, or processed by the system itself to generate one or morecommands. One example of command data is a collection of one or moretrades to be executed by financial exchanges. The commands may includeorders to automatically buy and/or sell financial instruments based onvarious rules or preconditions. These rules or preconditions may includebuying or selling if the market is at a certain price, if one or moretechnical indicators signals a purchase or sale, or if certain marketdata received from private or government entities contains particularvalues corresponding to a predetermined level (e.g. “new housingstarts”, “gross domestic product”, interest rates on government bonds,and the like).

A security protocol may optionally be applied to the command data (1508)as discussed herein elsewhere. Such security protocols may includeencrypting the command data using public or private key encryptiontechniques, applying an encoding algorithm such as two-way hashing, andthe like. Any suitable technique for securing command data may be usedto make the data unreadable or unusable by third parties.

Command data can be transmitted (1512) from a transmitting communicationnode to a receiving communications node. Any suitable technique forcommunicating command data may be used such as sending the command dataas a series of signals, packets, are datagrams of any suitable size. Thetransmission of either the command data, or the triggering data (orboth) may occur over a low latency low bandwidth communication link suchas communication link 104, or over a high latency high-bandwidthcommunication link such as communication link 108. Command data may alsobe transmitted by multiple communication links such as communicationlinks 104 and 108 sequentially or at about the same time. Thetransmitted command data may be received (1516) by a receivingcommunications node using any of the communication links discussedherein. The system may optionally check the integrity of the datareceived and may optionally coordinate with a transmitting communicationnode to automatically resend the data if portions of it were notreceived or were corrupted in transmission.

When command data has been received at a receiving communications node,the commands may be prepared for execution (1520). Such preparation mayinclude upgrading or replacing software stored in a memory on a computerto be executed by a processor or other circuitry when a triggering eventoccurs. In another example, preparing commands for execution at 1520 mayinclude programming a Field Programmable Gate Array (FPGA) toautomatically perform the commands. This process may occur by anysuitable means such as by performing a firmware upgrade on a computerthat uses an FPGA or similar reprogrammable circuitry. When the commandsof been prepared for execution, the system may then wait for atriggering event to take place (1524).

The system may execute various other activities while waiting for atriggering event to take place, examples of which are illustrated inFIG. 16 at 1408. If no triggering event has occurred (1602), variousactions may be taken by a communications node at either end of acommunications link, or at both ends. These actions may be the takencontinuously while waiting for a triggering event to take place.

At 1604, the system may determine a maximum usable frequency. Thisaction might be taken to maintain a communication link such as link 104that communicates via skywave propagation. The maximum usable frequencymay be automatically determined experimentally by using a processor likeprocessor 804 to control transmitter 904 to send signals over a broadrange of frequencies in the electromagnetic spectrum. The processor mayalso control receiver 908 to listen for responses from othertransmitting communication nodes. The processor may then analyze thesignal sent and the responses received to determine the maximum usablefrequency that may be used to achieve communication with various remotecommunications nodes.

In another example, the maximum usable frequency may be predicted ordetermined by propagation data provided by third parties such asgovernment entities. Such third parties may continuously monitor skywavepropagation across a broad range of frequencies and distances providingthis propagation data as an aid in calculating skip distances across arange of frequencies in the electromagnetic spectrum. Software modelingof distances, atmospheric conditions, and any other factors impactingpropagation may also be used to determine the maximum usable frequency.

The system may determine a minimum usable frequency at 1608. The minimumusable frequency may be determined experimentally as described above, orby receiving and processing updated third-party propagation data. Themaximum and minimum usable frequencies may then be stored (1612) in amemory accessible by the processor.

When the system is waiting for an event (1602), a communication node maytransmit a steady stream of signals that may or may not contain anyuseful data. The signals or data are prepared for transmission at 1616,and as discussed above, the transmission may or may not includemeaningful command data or triggering data. They communication node may,for example, send a transmission at a regular interval, or with aspecific sequence of data. In this way a communication node may maintaina communication link thereby quickly become aware when the communicationlink is compromised.

Where a communication link uses skywave propagation (such ascommunication link 104), the system may choose a transmission frequency(1620) using the processor or other logic circuit. Choosing atransmission frequency may include selecting a frequency between theminimum and maximum usable frequencies determined at 1604 and 1608. Thismay be done in accordance with a “frequency hopping” system configuredto repeatedly choose a different frequency over time for transmittingand receiving. Choosing a transmission frequency may also includeselecting a frequency from a predetermined set or range of frequenciessuch as in a spread spectrum “signal hopping” configuration. Thefrequency may be determined according to any suitable technique such asby Multiple-input/Multiple-output (MIMO) using multiple transmitters orreceivers at different frequencies. The data may then be transmitted(1624) once the transmission frequency is determined.

The actions illustrated in FIG. 16 may continue in parallel while thesystem waits for an event to occur (1602). When a triggering eventoccurs, triggering data can be sent (1412). Additional detail of actionsa system may take when triggering data is sent are illustrated in FIG.17 at 1412. Triggering data may be prepared (1704) which may includeextracting or receiving the triggering data from a third-party datasource and configuring it for transmission over a communications linksuch as communication link 104 or 108. A security protocol may beapplied to the triggering data (1708) to reduce or eliminate theopportunity for third-party individuals to obtain triggering datawithout authorization. Any suitable security protocol may be applied asdiscussed herein elsewhere.

A transmission frequency may then be chosen (1712). Examples includeselecting a frequency between the maximum and minimum usable frequenciesas previously determined, or by selecting a frequency from apredetermined set of frequencies such as in a “signal hopping”configuration. In another example, the system may transmit over multiplefrequencies a the same time. The system may then transmit the triggeringdata at 1716 along one or more communications links as discussed hereinelsewhere.

FIG. 18 illustrates additional detail of actions the system may takewhen receiving triggering data. As illustrated at 1416, a receivingcommunications node may receive triggering data at 1804. At 1808, asecurity protocol may be applied to unscramble, decrypt, decode, orotherwise remove any security measures that may have been applied whenthe triggering data was sent. A processor may then process thetriggering data to identify commands to execute (1812) based on anidentifier sent in the triggering data. Triggering data may also includemultiple identifiers i

identifying multiple commands to execute. The system may then executethe commands (1816) identified in the triggering data.

Glossary of Definitions and Alternatives

The language used in the claims and specification is to only have itsplain and ordinary meaning, except as explicitly defined below. Thewords in these definitions are to only have their plain and ordinarymeaning. Such plain and ordinary meaning is inclusive of all consistentdictionary definitions from the most recently published Webster's andRandom House dictionaries. As used in the specification and claims, thefollowing definitions apply to the following terms or common variationsthereof (e.g., singular/plural forms, past/present tenses, etc.):

“Antenna” or “Antenna system” generally refers to an electrical device,or series of devices, in any suitable configuration, that convertselectric power into electromagnetic radiation. Such radiation may beeither vertically, horizontally, or circularly polarized at anyfrequency along the electromagnetic spectrum. Antennas transmitting withcircular polarity may have either right-handed or left-handedpolarization.

In the case of radio waves, an antenna may transmit at frequenciesranging along electromagnetic spectrum from extremely low frequency(ELF) to extremely high frequency (EHF). An antenna or antenna systemdesigned to transmit radio waves may comprise an arrangement of metallicconductors (elements), electrically connected (often through atransmission line) to a receiver or transmitter. An oscillating currentof electrons forced through the antenna by a transmitter can create anoscillating magnetic field around the antenna elements, while the chargeof the electrons also creates an oscillating electric field along theelements. These time-varying fields radiate away from the antenna intospace as a moving transverse electromagnetic field wave. Conversely,during reception, the oscillating electric and magnetic fields of anincoming electromagnetic wave exert force on the electrons in theantenna elements, causing them to move back and forth, creatingoscillating currents in the antenna. These currents can then be detectedby receivers and processed to retrieve digital or analog signals ordata.

Antennas can be designed to transmit and receive radio wavessubstantially equally in all horizontal directions (omnidirectionalantennas), or preferentially in a particular direction (directional orhigh gain antennas). In the latter case, an antenna may also includeadditional elements or surfaces which may or may not have any physicalelectrical connection to the transmitter or receiver. For example,parasitic elements, parabolic reflectors or horns, and other suchnon-energized elements serve to direct the radio waves into a beam orother desired radiation pattern. Thus antennas may be configured toexhibit increased or decreased directionality or “gain” by the placementof these various surfaces or elements. High gain antennas can beconfigured to direct a substantially large portion of the radiatedelectromagnetic energy in a given direction that may be verticalhorizontal or any combination thereof.

Antennas may also be configured to radiate electromagnetic energy withina specific range of vertical angles (i.e. “takeoff angles) relative tothe earth in order to focus electromagnetic energy toward an upper layerof the atmosphere such as the ionosphere. By directing electromagneticenergy toward the upper atmosphere at a specific angle, specific skipdistances may be achieved at particular times of day by transmittingelectromagnetic energy at particular frequencies.

Other examples of antennas include emitters and sensors that convertelectrical energy into pulses of electromagnetic energy in the visibleor invisible light portion of the electromagnetic spectrum. Examplesinclude light emitting diodes, lasers, and the like that are configuredto generate electromagnetic energy at frequencies ranging along theelectromagnetic spectrum from far infrared to extreme ultraviolet.

“Command” or “Command Data” generally refers to one or more directives,instructions, algorithms, or rules controlling a machine to take one ormore actions, alone or in combination. A command may be stored,transferred, transmitted, or otherwise processed in any suitable manner.For example, a command may be stored in a memory or transmitted over acommunication network as electromagnetic radiation at any suitablefrequency passing through any suitable medium.

“Computer” generally refers to any computing device configured tocompute a result from any number of input values or variables. Acomputer may include a processor for performing calculations to processinput or output. A computer may include a memory for storing values tobe processed by the processor, or for storing the results of previousprocessing.

A computer may also be configured to accept input and output from a widearray of input and output devices for receiving or sending values. Suchdevices include other computers, keyboards, mice, visual displays,printers, industrial equipment, and systems or machinery of all typesand sizes. For example, a computer can control a network interface toperform various network communications upon request. The networkinterface may be part of the computer, or characterized as separate andremote from the computer.

A computer may be a single, physical, computing device such as a desktopcomputer, a laptop computer, or may be composed of multiple devices ofthe same type such as a group of servers operating as one device in anetworked cluster, or a heterogeneous combination of different computingdevices operating as one computer and linked together by a communicationnetwork. The communication network connected to the computer may also beconnected to a wider network such as the internet. Thus computer mayinclude one or more physical processors or other computing devices orcircuitry, and may also include any suitable type of memory.

A computer may also be a virtual computing platform having an unknown orfluctuating number of physical processors and memories or memorydevices. A computer may thus be physically located in one geographicallocation or physically spread across several widely scattered locationswith multiple processors linked together by a communication network tooperate as a single computer.

The concept of “computer” and “processor” within a computer or computingdevice also encompasses any such processor or computing device servingto make calculations or comparisons as part of disclosed system.Processing operations related to threshold comparisons, rulescomparisons, calculations, and the like occurring in a computer mayoccur, for example, on separate servers, the same server with separateprocessors, or on a virtual computing environment having an unknownnumber of physical processors as described above.

A computer may be optionally coupled to one or more visual displaysand/or may include an integrated visual display. Likewise, displays maybe of the same type, or a heterogeneous combination of different visualdevices. A computer may also include one or more operator input devicessuch as a keyboard, mouse, touch screen, laser or infrared pointingdevice, or gyroscopic pointing device to name just a few representativeexamples. Also, besides a display, one or more other output devices maybe included such as a printer, plotter, industrial manufacturingmachine, 3D printer, and the like. As such, various display, input andoutput device arrangements are possible.

Multiple computers or computing devices may be configured to communicatewith one another or with other devices over wired or wirelesscommunication links to form a communication network. Networkcommunications may pass through various computers operating as networkappliances such as switches, routers, firewalls or other network devicesor interfaces before passing over other larger computer networks such asthe internet. Communications can also be passed over the communicationnetwork as wireless data transmissions carried over electromagneticwaves through transmission lines or free space. Such communicationsinclude using WiFi or other Wireless Local Area Network (WLAN) or acellular transmitter/receiver to transfer data. Such signals conform toany of a number of wireless or mobile telecommunications technologystandards such as 802.11a/b/g/n, 3G, 4G, and the like.

“Communication Link” generally refers to a connection between two ormore communicating entities and may or may not include a communicationschannel between the communicating entities. The communication betweenthe communicating entities may occur by any suitable means. For examplethe connection may be implemented as an actual physical link, anelectrical link, an electromagnetic link, a logical link, or any othersuitable linkage facilitating communication.

In the case of an actual physical link, communication may occur bymultiple components in the communication link figured to respond to oneanother by physical movement of one element in relation to another. Inthe case of an electrical link, the communication link may be composedof multiple electrical conductors electrically connected to form thecommunication link.

In the case of an electromagnetic link, elements the connection may beimplemented by sending or receiving electromagnetic energy at anysuitable frequency, thus allowing communications to pass aselectromagnetic waves. These electromagnetic waves may or may not passthrough a physical medium such as an optical fiber, or through freespace, or any combination thereof. Electromagnetic waves may be passedat any suitable frequency including any frequency in the electromagneticspectrum.

In the case of a logical link, the communication link may be aconceptual linkage between the sender and recipient such as atransmission station in the receiving station. Logical link may includeany combination of physical, electrical, electromagnetic, or other typesof communication links.

“Communication node” generally refers to a physical or logicalconnection point, redistribution point or endpoint along a communicationlink. A physical network node is generally referred to as an activeelectronic device attached or coupled to a communication link, eitherphysically, logically, or electromagnetically. A physical node iscapable of sending, receiving, or forwarding information over acommunication link. A communication node may or may not include acomputer, processor, transmitter, receiver, repeater, and/ortransmission lines, or any combination thereof.

“Critical angle” generally refers to the highest angle with respect to avertical line extending to the center of the Earth at which anelectromagnetic wave at a specific frequency can be returned to theEarth using sky-wave propagation.

“Critical Frequency” generally refers to the highest frequency that willbe returned to the Earth when transmitted vertically under givenionospheric conditions using sky-wave propagation.

“Data Bandwidth” generally refers to the maximum throughput of a logicalor physical communication path in a communication system. Data bandwidthis a transfer rate that can be expressed in units of data transferredper second. In a digital communications network, the units of datatransferred are bits and the maximum throughput of a digitalcommunications network is therefore generally expressed in “bits persecond” or “bit/s.” By extension, the terms “kilobit/s” or “Kbit/s”,“Megabit/s” or “Mbit/s”, and “Gigabit/s” or “Gbit/s” can also be used toexpress the data bandwidth of a given digital communications network.Data networks may be rated according to their data bandwidth performancecharacteristics according to specific metrics such as “peak bit rate”,“mean bit rate”, “maximum sustained bit rate”, “information rate”, or“physical layer useful bit rate.” For example, bandwidth tests measurethe maximum throughput of a computer network. The reason for this usageis that according to Hartley's Law, the maximum data rate of a physicalcommunication link is proportional to its frequency bandwidth in hertz.

Data bandwidth may also be characterized according to the maximumtransfer rate for a particular communications network. For example:

-   -   “Low Data Bandwidth” generally refers to a communications        network with a maximum data transfer rate that is less than or        about equal to 1,000,000 units of data per second. For example,        in a digital communications network, the unit of data is a bit.        Therefore low data bandwidth digital communications networks are        networks with a maximum transfer rate that is less than or about        equal to 1,000,000 bits per second (1 Mbits/s).    -   “High Data Bandwidth” generally refers to a communications        network with a maximum data transfer rate that is greater than        about 1,000,000 units of data per second. For example, a digital        communications network with a high data bandwidth is a digital        communications network with a maximum transfer rate that is        greater than about 1,000,000 bits per second (1 Mbits/s).

“Electromagnet Radiation” generally refers to energy radiated byelectromagnetic waves. Electromagnetic radiation is produced from othertypes of energy, and is converted to other types when it is destroyed.Electromagnetic radiation carries this energy as it travels moving awayfrom its source at the speed of light (in a vacuum). Electromagneticradiation also carries both momentum and angular momentum. Theseproperties may all be imparted to matter with which the electromagneticradiation interacts as it moves outwardly away from its source.

Electromagnetic radiation changes speed as it passes from one medium toanother. When transitioning from one media to the next, the physicalproperties of the new medium can cause some or all of the radiatedenergy to be reflected while the remaining energy passes into the newmedium. This occurs at every junction between media that electromagneticradiation encounters as it travels.

The photon is the quantum of the electromagnetic interaction, and is thebasic constituent of all forms of electromagnetic radiation. The quantumnature of light becomes more apparent at high frequencies aselectromagnetic radiation behaves more like particles and less likewaves as its frequency increases.

“Electromagnetic Spectrum” generally refers to the range of all possiblefrequencies of electromagnetic radiation. The electromagnetic spectrumis generally categorized as follows, in order of increasing frequencyand energy and decreasing wavelength:

-   -   “Extremely low frequency” (ELF) generally designates a band of        frequencies from about 3 to about 30 Hz with wavelengths from        about 100,000 to 10,000 km long.    -   “Super low frequency” (SLF) generally designates a band of        frequencies generally ranging between about 30 Hz to about 300        Hz with wavelengths of about 10,000 to about 1000 km long.    -   “Voice frequency” or “voice band” generally designates        electromagnetic energy that is audibles to the human ear. Adult        males generally speak in the range between about 85 and about        180 Hz while adult females generally converse in the range from        about 165 to about 255 Hz.    -   “Very low frequency” (VLF) generally designates the band of        frequencies from about 3 kHz to about 30 kHz with corresponding        wavelengths from about 10 to about 100 km long.    -   “Low-frequency” (LF) generally designates the band of        frequencies in the range of about 30 kHz to about 300 kHz with        wavelengths range from about 1 to about 10 km.    -   “Medium frequency” (MF) generally designates the band of        frequencies from about 300 kHz to about 3 MHz with wavelengths        from about 1000 to about 100 m long.    -   “High frequency” (I-IF) generally designates the band of        frequencies from about 3 MHz to about 30 MHz having wavelengths        from about 100 m to about 10 m long.    -   “Very high frequency” (VHF) generally designates the band of        frequencies from about 30 Hz to about 300 MHz with wavelengths        from about 10 m to about 1 m long.    -   “Ultra high frequency” (UHF) generally designates the band of        frequencies from about 300 MHz to about 3 GHz with weight        wavelengths ranging from about 1 m to about 10 cm long.    -   “Super high frequency” (SHF) generally designates the band of        frequencies from about 3 GHz to about 30 GHz with wavelengths        ranging from about 10 cm to about 1 cm long.    -   “Extremely high frequency” (EHF) generally designates the band        of frequencies from about 30 GHz to about 300 GHz with        wavelengths ranging from about 1 cm to about 1 mm long.    -   “Far infrared” (FIR) generally designates a band of frequencies        from about 300 GHz to about 20 THz with wavelengths ranging from        about 1 mm to about 15 μm long.    -   “Long-wavelength infrared” (LWIR) generally designates a band of        frequencies from about 20 THz to about 37 THz with wavelengths        ranging from about 15 μm to about 8 μm long.    -   “Mid infrared” (MIR) generally designates a band of frequencies        from about 37 THz to about 100 THz with wavelengths from about 8        μm to about 3 μm long.    -   “Short wavelength infrared” (SWIR) generally designates a band        of frequencies from about 100 THz to about 214 THz with        wavelengths from about 3 μm to about 1.4 μm long    -   “Near-infrared” (NIR) generally designates a band of frequencies        from about 214 THz to about 400 THz with wavelengths from about        1.4 μm to about 750 nm long.    -   “Visible light” generally designates a band of frequencies from        about 400 THz to about 750 THz with wavelengths from about 750        nm to about 400 nm long.    -   “Near ultraviolet” (NUV) generally designates a band of        frequencies from about 750 THz to about 1 PHz with wavelengths        from about 400 nm to about 300 nm long.    -   “Middle ultraviolet” (MUV) generally designates a band of        frequencies from about 1 PHz to about 1.5 PHz with wavelengths        from about 300 nm to about 200 nm long.    -   “Far ultraviolet” (FUV) generally designates a band of        frequencies from about 1.5 PHz to about 2.48 PHz with        wavelengths from about 200 nm to about 122 nm long.    -   “Extreme ultraviolet” (EUV) generally designates a band of        frequencies from about 2.48 PHz to about 30 PHz with wavelengths        from about 121 nm to about 10 nm long.    -   “Soft x-rays” (SX) generally designates a band of frequencies        from about 30 PHz to about 3 EHz with wavelengths from about 10        nm to about 100 μm long.    -   “Hard x-rays” (HX) generally designates a band of frequencies        from about 3 EHz to about 30 EHz with wavelengths from about 100        μm to about 10 μm long.    -   “Gamma rays” generally designates a band of frequencies above        about 30 EHz with wavelengths less than about 10 μm long.

“Electromagnetic Waves” generally refers to waves having a separateelectrical and a magnetic component. The electrical and magneticcomponents of an electromagnetic wave oscillate in phase and are alwaysseparated by a 90 degree angle. Electromagnetic waves can radiate from asource to create electromagnetic radiation capable of passing through amedium or through a vacuum. Electromagnetic waves include wavesoscillating at any frequency in the electromagnetic spectrum including,but not limited to, radio waves, visible and invisible light, X-rays,and gamma-rays.

“Frequency Bandwidth” or “Band” generally refers to a contiguous rangeof frequencies defined by an upper and lower frequency. Frequencybandwidth is thus typically expressed as a number of hertz (cycles persecond) representing the difference between the upper frequency and thelower frequency of the band and may or may not include the upper andlower frequencies themselves. A “band” can therefore be defined by agiven frequency bandwidth for a given region and designated withgenerally agreed on terms. For example, the “20 meter band” in theUnited States is assigned the frequency range from 14 MHz to 14.35 MHzthus defining a frequency bandwidth of 0.35 MHz or 350 KHz. In anotherexample, the International Telecommunication Union (ITU) has designatedthe frequency range from 300 Mhz to 3 GHz as the “UHF band”.

“Fiber-optic communication” generally refers to a method of transmittingdata from one place to another by sending pulses of electromagneticenergy through an optical fiber. The transmitted energy may form anelectromagnetic carrier wave that can be modulated to carry data.Fiber-optic communication lines that use optical fiber cables totransmit data can be configured to have a high data bandwidth. Forexample, fiber-optic communication lines may have a high data bandwidthof up to about 15 Tbit/s, about 25 Tbit/s, about 100 Tbit/s, about 1Pbit/s or more. Opto-electronic repeaters may be used along afiber-optic communication line to convert the electromagnetic energyfrom one segment of fiber-optic cable into an electrical signal. Therepeater can retransmit the electrical signal as electromagnetic energyalong another segment of fiber-optic cable at a higher signal strengththan it was received.

“Financial instrument” generally refers to a tradable asset of any kind.General examples include, but are not limited to, cash, evidence of anownership interest in an entity, or a contractual right to receive ordeliver cash or another financial instrument. Specific examples includebonds, bills (e.g. commercial paper and treasury bills), stock, loans,deposits, certificates of deposit, bond futures or options on bondfutures, short-term interest rate futures, stock options, equityfutures, currency futures, interest rate swaps, interest rate caps andfloors, interest rate options, forward rate agreements, stock options,foreign-exchange options, foreign-exchange swaps, currency swaps, or anysort of derivative.

“Ground” is used more in an electrical/electromagnetic sense andgenerally refers to the Earth's surface including land and bodies ofwater, such as oceans, lakes, and rivers.

“Ground-wave propagation” generally refers to a transmission method inwhich one or more electromagnetic waves are conducted via the boundaryof the ground and atmosphere to travel along ground. The electromagneticwave propagates by interacting with the semi-conductive surface of theearth. In essence, the wave clings to the surfaces so as to follow thecurvature of the earth. Typically, but not always, the electromagneticwave is in the form of a ground or surface wave formed by low-frequencyradio waves.

“Identifier” generally refers to a name that identifies (that is, labelsthe identity of) either a unique thing or a unique class of things,where the “object” or class may be an idea, physical object (or classthereof), or physical substance (or class thereof). The abbreviation“ID” often refers to identity, identification (the process ofidentifying), or an identifier (that is, an instance of identification).An identifier may or may not include words, numbers, letters, symbols,shapes, colors, sounds, or any combination of those.

The words, numbers, letters, or symbols may follow an encoding system(wherein letters, digits, words, or symbols represent ideas or longeridentifiers) or they may simply be arbitrary. When an identifier followsan encoding system, it is often referred to as a code or ID code.Identifiers that do not follow any encoding scheme are often said to bearbitrary IDs because they are arbitrarily assigned without meaning inany other context beyond identifying something

“Ionosphere” generally refers to the layer of the Earth's atmospherethat contains a high concentration of ions and free electrons and isable to reflect radio waves. The ionosphere includes the thermosphere aswell as parts of the mesosphere and exosphere. The ionosphere extendsfrom about 25 to about 600 miles (about 40 to 1,000 km) above theearth's surface. The ionosphere includes a number of layers that undergoconsiderable variations in altitude, density, and thickness, dependingamong a number of factors including solar activity, such as sunspots.The various layers of the ionosphere are identified below.

-   -   The “D layer” of the ionosphere is the innermost layer that        ranges from about 25 miles (40 km) to about 55 miles (90 km)        above the Earth's surface. The layer has the ability to refract        signals of low frequencies, but it allows high frequency radio        signals to pass through with some attenuation. The D layer        normally, but not in all instances, disappears rapidly after        sunset due to rapid recombination of its ions.    -   The “E layer” of the ionosphere is the middle layer that ranges        from about 55 miles (90 km) to about 90 miles (145 km) above the        Earth's surface. The E layer typically has the ability to        refract signals with frequencies higher than the D layer.        Depending on the conditions, the E layer can normally refract        frequencies up to 20 MHz. The rate of ionic recombination in the        E layer is somewhat rapid such that after sunset it almost        completely disappears by midnight. The E layer can further        include what is termed an “E_(s)-layer” or “sporadic E layer”        that is formed by small, thin clouds of intense ionization. The        sporadic E layer can reflect radio waves, even frequencies up to        225 MHz, although rarely. Sporadic E layers most often form        during summer months, and it has skip distances of around 1,020        miles (1,640 km). With the sporadic E layer, one hop propagation        can be about 560 miles (900 km) to up to 1,600 miles (2,500 km),        and double hop propagation can be over 2,200 miles (3,500 km).    -   The “F layer” of the ionosphere is the top layer that ranges        from about 90 (145 km) to 310 miles (500 km) or more above the        Earth's surface. The ionization in the F layer is typically        quite high and varies widely during the day, with the highest        ionization occurring usually around noon. During daylight, the F        layer separates into two layers, the F₁ layer and the F₂ layer.        The F₂ layer is outermost layer and, as such, is located higher        than the F₁ layer. Given the atmosphere is rarified at these        altitudes, the recombination of ions occur slowly such that F        layer remains constantly ionized, either day or night such that        most (but not all) skywave propagation of radio waves occur in        the F layer, thereby facilitating high frequency (HF) or short        wave communication over long distances. For example, the F        layers are able to refract high frequency, long distance        transmissions for frequencies up to 30 MHz.

“Latency” generally refers to the time interval between a cause and aneffect in a system. Latency is physically a consequence of the limitedvelocity with which any physical interaction can propagate throughout asystem. Latency is physically a consequence of the limited velocity withwhich any physical interaction can propagate. The speed at which aneffect can propagate through a system is always lower than or equal tothe speed of light. Therefore every physical system that includes somedistance between the cause and the effect will experience some kind oflatency. For example, in a communication link or communications network,latency generally refers to the minimum time it takes for data to passfrom one point to another. Latency with respect to communicationsnetworks may also be characterized as the time it takes energy to movefrom one point along the network to another. With respect to delayscaused by the propagation of electromagnetic energy following aparticular propagation path, latency can be categorized as follows:

-   -   “Low Latency” generally refers to a period of time that is less        than or about equal to a propagation time that is 10% greater        than the time required for light to travel a given propagation        path in a vacuum. Expressed as a formula, low latency is defined        as follows:

$\begin{matrix}{{latency}_{low} \leq {\frac{d}{c} \cdot k}} & \left( {{Equation}\mspace{14mu} 1} \right)\end{matrix}$

-   -   where:        -   d=distance (miles)        -   c=the speed of light in a vacuum (186,000 miles/sec)        -   k=a scalar constant of 1.1    -   For example, light can travel 25,000 miles through a vacuum in        about 0.1344 seconds. A “low latency” communication link        carrying data over this 25,000 mile propagation path would        therefore be capable of passing at least some portion of the        data over the link in about 0.14784 seconds or less.    -   “High Latency” generally refers to a period of time that is over        10% greater than the time required for light to travel a given        propagation path in a vacuum. Expressed as a formula, high        latency is defined as follows:

$\begin{matrix}{{latency}_{high} > {\frac{d}{c} \cdot k}} & \left( {{Equation}\mspace{14mu} 2} \right)\end{matrix}$

-   -   where:        -   d=distance (miles)        -   c=the speed of light in a vacuum (186,000 miles/sec)        -   k=a scalar constant of 1.1    -   For example, light can travel 8,000 miles through a vacuum in        about 0.04301 seconds. A “high latency” communication link        carrying data over this transmission path would therefore be        capable of passing at least some portion of the data over the        link in about 0.04731 seconds or more.    -   The “high” and “low” latency of a network may be independent of        the data bandwidth. Some “high” latency networks may have a high        transfer rate that is higher than a “low” latency network, but        this may not always be the case. Some “low” latency networks may        have a data bandwidth that exceeds the bandwidth of a “high”        latency network.

“Maximum Usable Frequency (MUF)” generally refers to the highestfrequency that is returned to the Earth using sky-wave propagation.

“Memory” generally refers to any storage system or device configured toretain data or information Each memory may include one or more types ofsolid-state electronic memory, magnetic memory, or optical memory, justto name a few. By way of non-limiting example, each memory may includesolid-state electronic Random Access Memory (RAM), SequentiallyAccessible Memory (SAM) (such as the First-In, First-Out (FIFO) varietyor the Last-In-First-Out (LIFO) variety), Programmable Read Only Memory(PROM), Electronically Programmable Read Only Memory (EPROM), orElectrically Erasable Programmable Read Only Memory (EEPROM); an opticaldisc memory (such as a DVD or CD ROM); a magnetically encoded hard disc,floppy disc, tape, or cartridge media; or a combination of any of thesememory types. Also, each memory may be volatile, nonvolatile, or ahybrid combination of volatile and nonvolatile varieties.

“Non-sky-wave propagation” generally refers to all forms oftransmission, wired and/or wireless, in which the information is nottransmitted by reflecting an electromagnetic wave from the ionosphere.

“Optimum Working Frequency” generally refers to the frequency thatprovides the most consistent communication path via sky-wavepropagation. It can vary over time depending on number of factors, suchas ionospheric conditions and time of day. For transmissions using theF₂ layer of the ionosphere the working frequency is generally around 85%of the MUF, and for the E layer, the optimum working frequency willgenerally be near the MUF.

“Optical Fiber” generally refers to an electromagnetic waveguide havingan elongate conduit that includes a substantially transparent mediumthrough which electromagnetic energy travels as it traverses the longaxis of the conduit. Electromagnetic radiation may be maintained withinthe conduit by total internal reflection of the electromagneticradiation as it traverses the conduit. Total internal reflection isgenerally achieved using optical fibers that include a substantiallytransparent core surrounded by a second substantially transparentcladding material with a lower index of refraction than the core.

Optical fibers are generally constructed of dielectric material that isnot electrically conductive but is substantially transparent. Suchmaterials may or may not include any combination of extruded glass suchas silica, fluoride glass, phosphate glass, Chalcogenide glass, orpolymeric material such as various types of plastic, or other suitablematerial and may be configured with any suitable cross-sectional shape,length, or dimension. Examples of electromagnetic energy that may besuccessfully passed through optical fibers include electromagnetic wavesin the near-infrared, mid-infrared, and visible light portion of theelectromagnetic spectrum, although electromagnetic energy of anysuitable frequency may be used.

“Polarization” generally refers to the orientation of the electric field(“E-plane”) of a radiated electromagnetic energy wave with respect tothe Earth's surface and is determined by the physical structure andorientation of the radiating antenna. Polarization can be consideredseparately from an antenna's directionality. Thus, a simple straightwire antenna may have one polarization when mounted abstention thevertically, and a different polarization when mounted substantiallyhorizontally. As a transverse wave, the magnetic field of a radio waveis at right angles to that of the electric field, but by convention,talk of an antenna's “polarization” is understood to refer to thedirection of the electric field.

Reflections generally affect polarization. For radio waves, oneimportant reflector is the ionosphere which can change the wave'spolarization. Thus for signals received via reflection by the ionosphere(a skywave), a consistent polarization cannot be expected. Forline-of-sight communications or ground wave propagation, horizontally orvertically polarized transmissions generally remain in about the samepolarization state at the receiving location. Matching the receivingantenna's polarization to that of the transmitter may be especiallyimportant in ground wave or line of sight propagation but may be lessimportant in skywave propagation.

An antenna's linear polarization is generally along the direction (asviewed from the receiving location) of the antenna's currents when sucha direction can be defined. For instance, a vertical whip antenna orWi-Fi antenna vertically oriented will transmit and receive in thevertical polarization. Antennas with horizontal elements, such as mostrooftop TV antennas, are generally horizontally polarized (becausebroadcast TV usually uses horizontal polarization). Even when theantenna system has a vertical orientation, such as an array ofhorizontal dipole antennas, the polarization is in the horizontaldirection corresponding to the current flow.

Polarization is the sum of the E-plane orientations over time projectedonto an imaginary plane perpendicular to the direction of motion of theradio wave. In the most general case, polarization is elliptical,meaning that the polarization of the radio waves varies over time. Twospecial cases are linear polarization (the ellipse collapses into aline) as we have discussed above, and circular polarization (in whichthe two axes of the ellipse are equal). In linear polarization theelectric field of the radio wave oscillates back and forth along onedirection; this can be affected by the mounting of the antenna butusually the desired direction is either horizontal or verticalpolarization. In circular polarization, the electric field (and magneticfield) of the radio wave rotates At the radio frequency circularlyaround the axis of propagation.

“Processor” generally refers to one or more electronic componentsconfigured to operate as a single unit configured or programmed toprocess input to generate an output. Alternatively, when of amulti-component form, a processor may have one or more componentslocated remotely relative to the others. One or more components of eachprocessor may be of the electronic variety defining digital circuitry,analog circuitry, or both. In one example, each processor is of aconventional, integrated circuit microprocessor arrangement, such as oneor more PENTIUM, i3, i5 or i7 processors supplied by INTEL Corporationof 2200 Mission College Boulevard, Santa Clara, Calif. 95052, USA.

Another example of a processor is an Application-Specific IntegratedCircuit (ASIC). An ASIC is an Integrated Circuit (IC) customized toperform a specific series of logical operations is controlling thecomputer to perform specific tasks or functions. An ASIC is an exampleof a processor for a special purpose computer, rather than a processorconfigured for general-purpose use. An application-specific integratedcircuit generally is not reprogrammable to perform other functions andmay be programmed once when it is manufactured.

In another example, a processor may be of the “field programmable” type.Such processors may be programmed multiple times “in the field” toperform various specialized or general functions after they aremanufactured. A field-programmable processor may include aField-Programmable Gate Array (FPGA) in an integrated circuit in theprocessor. FPGA may be programmed to perform a specific series ofinstructions which may be retained in nonvolatile memory cells in theFPGA. The FPGA may be configured by a customer or a designer using ahardware description language (HDL). In FPGA may be reprogrammed usinganother computer to reconfigure the FPGA to implement a new set ofcommands or operating instructions. Such an operation may be executed inany suitable means such as by a firmware upgrade to the processorcircuitry.

Just as the concept of a computer is not limited to a single physicaldevice in a single location, so also the concept of a “processor” is notlimited to a single physical logic circuit or package of circuits butincludes one or more such circuits or circuit packages possiblycontained within or across multiple computers in numerous physicallocations. In a virtual computing environment, an unknown number ofphysical processors may be actively processing data, the unknown numbermay automatically change over time as well.

The concept of a “processor” includes a device configured or programmedto make threshold comparisons, rules comparisons, calculations, orperform logical operations applying a rule to data yielding a logicalresult (e.g. “true” or “false”). Processing activities may occur inmultiple single processors on separate servers, on multiple processorsin a single server with separate processors, or on multiple processorsphysically remote from one another in separate computing devices.

“Radio” generally refers to electromagnetic radiation in the frequenciesthat occupy the range from 3 kHz to 300 GHz.

“Radio horizon” generally refers the locus of points at which directrays from an antenna are tangential to the ground. The radio horizon canbe approximated by the following equation:

d≅√{square root over (2h_(t))}+√{square root over (2h_(r))}  (Equation3)

-   -   where:        -   d=radio horizon (miles)        -   h_(t)=transmitting antenna height (feet)        -   h_(r)=receiving antenna height (feet).

“Remote” generally refers to any physical, logical, or other separationbetween two things. The separation may be relatively large, such asthousands or millions of miles or kilometers, or small such asnanometers or millionths of an inch. Two things “remote” from oneanother may also be logically or physically coupled or connectedtogether.

“Receive” generally refers to accepting something transferred,communicated, conveyed, relayed, dispatched, or forwarded. The conceptmay or may not include the act of listening or waiting for something toarrive from a transmitting entity. For example, a transmission may bereceived without knowledge as to who or what transmitted it. Likewisethe transmission may be sent with or without knowledge of who or what isreceiving it. To “receive” may include, but is not limited to, the actof capturing or obtaining electromagnetic energy at any suitablefrequency in the electromagnetic spectrum. Receiving may occur bysensing electromagnetic radiation. Sensing electromagnetic radiation mayinvolve detecting energy waves moving through or from a medium such as awire or optical fiber. Receiving includes receiving digital signalswhich may define various types of analog or binary data such as signals,datagrams, packets and the like.

“Receiving Station” generally refers to a receiving device, or to alocation facility having multiple devices configured to receiveelectromagnetic energy. A receiving station may be configured to receivefrom a particular transmitting entity, or from any transmitting entityregardless of whether the transmitting entity is identifiable in advanceof receiving the transmission.

“Skip distance” generally refers to the minimum distance from atransmitter to where a wave from sky-wave propagation can be returned tothe Earth. To put it another way, the skip distance is the minimumdistance that occurs at the critical angle for sky-wave propagation.

“Skip zone” or “quiet zone” generally refers to is an area between thelocation where a ground wave from ground wave propagation is completelydissipated and the location where the first sky wave returns using skywave propagation. In the skip zone, no signal for a given transmissioncan be received.

“Satellite communication” or “satellite propagation” generally refers totransmitting one or more electromagnetic signals to a satellite which inturn reflects and/or retransmits the signal to another satellite orstation.

“Size” generally refers to the extent of something; a thing's overalldimensions or magnitude; how big something is. For physical objects,size may be used to describe relative terms such as large or larger,high or higher, low or lower, small or smaller, and the like. Size ofphysical objects may also be given in fixed units such as a specificwidth, length, height, distance, volume, and the like expressed in anysuitable units.

For data transfer, size may be used to indicate a relative or fixedquantity of data being manipulated, addressed, transmitted, received, orprocessed as a logical or physical unit. Size may be used in conjunctionwith the amount of data in a data collection, data set, data file, orother such logical unit. For example, a data collection or data file maybe characterized as having a “size” of 35 Mbytes, or a communicationlink may be characterized as having a data bandwidth with a “size” of1000 bits per second.

“Sky-wave propagation” refers generally to a transmission method inwhich one or more electromagnetic-waves radiated from an antenna arerefracted from the ionosphere back to the ground. Sky-wave propagationfurther includes tropospheric scatter transmissions. In one form, askipping method can be used in which the waves refracted from theionosphere are reflected by the ground back up to the ionosphere. Thisskipping can occur more than once.

“Space-wave propagation” or sometimes referred to as “direct wavepropagation” or “line-of-sight propagation” generally refers to atransmission method in which one or more electromagnetic waves aretransmitted between antennas that are generally visible to one another.The transmission can occur via direct and/or ground reflected spacewaves. Generally speaking, the antenna height and curvature of the earthare limiting factors for the transmission distances for space-wavepropagation. The actual radio horizon for a direct line of sight islarger than the visible or geometric line of sight due to diffractioneffects; that is, the radio horizon is about 4/5 greater than thegeometric line of sight.

“Spread spectrum” generally refers to a transmission method thatincludes sending a portion of a transmitted signal over multiplefrequencies. The transmission over multiple frequencies may occursimultaneously by sending a portion of the signal on variousfrequencies. In this example, a receiver must listen to all frequenciessimultaneously in order to reassemble the transmitted signal. Thetransmission may also be spread over multiple frequencies by “hopping”signals. A signal hopping scenario includes transmitting the signal forsome period of time over a first frequency, switching to transmit thesignal over a second frequency for a second period of time, beforeswitching to a third frequency for a third period of time, and so forth.The receiver and transmitter must be synchronized in order to switchfrequencies together. This process of “hopping” frequencies may beimplemented in a frequency-hopping pattern that may change over time(e.g. every hour, every 24 hours, and the like).

“Stratosphere” generally refers to a layer of the Earth's atmosphereextending from the troposphere to about 25 to 35 miles above the earthsurface.

“Transfer Rate” generally refers to the rate at which a something ismoved from one physical or logical location to another. In the case of acommunication link or communication network, a transfer rate may becharacterized as the rate of data transfer over the link or network.Such a transfer rate may be expressed in “bits per second” and may belimited by the maximum data bandwidth for a given network orcommunication link used to carry out a transfer of data.

“Transmission line” generally refers to a specialized physical structureor series of structures designed to carry electromagnetic energy fromone location to another, usually without radiating the electromagneticenergy through free space. A transmission line operates to retain andtransfer electromagnetic energy from one location to another whileminimizing latency and power losses incurred as the electromagneticenergy passes through the structures in the transmission line.

Examples of transmission lines that may be used in communicating radiowaves include twin lead, coaxial cable, microstrip, strip line,twisted-pair, star quad, lecher lines, various types of waveguide, or asimple single wire line. Other types of transmission lines such asoptical fibers may be used for carrying higher frequency electromagneticradiation such as visible or invisible light.

“Transmission Path” or “Propagation Path” generally refers to path takenby electromagnetic energy passing through space or through a medium.This can include transmissions through a transmission line. In thiscase, the transmission path is defined by, follows, is contained within,passes through, or generally includes the transmission line. Atransmission or propagation path need not be defined by a transmissionline. A propagation or transmission path can be defined byelectromagnetic energy moving through free space or through theatmosphere such as in skywave, ground wave, line-of-site, or other formsof propagation. In that case, the transmission path can be characterizedas any path along which the electromagnetic energy passes as it is movesfrom the transmitter to the receiver, including any skip, bounce,scatter, or other variations in the direction of the transmitted energy.

“Transmission Station” generally refers to a transmitting device, or toa location or facility having multiple devices configured to transmitelectromagnetic energy. A transmission station may be configured totransmit to a particular receiving entity, to any entity configured toreceive transmission, or any combination thereof.

“Transmit” generally refers to causing something to be transferred,communicated, conveyed, relayed, dispatched, or forwarded. The conceptmay or may not include the act of conveying something from atransmitting entity to a receiving entity. For example, a transmissionmay be received without knowledge as to who or what transmitted it.Likewise the transmission may be sent with or without knowledge of whoor what is receiving it. To “transmit” may include, but is not limitedto, the act of sending or broadcasting electromagnetic energy at anysuitable frequency in the electromagnetic spectrum. Transmissions mayinclude digital signals which may define various types of binary datasuch as datagrams, packets and the like. A transmission may also includeanalog signals.

“Triggering Data” generally refers to data that includes triggeringinformation identifying one or more commands to execute. The triggeringdata and the command data may occur together in a single transmission ormay be transmitted separately along a single or multiple communicationlinks.

“Troposphere” generally refers to the lowest portion of the Earth'satmosphere. The troposphere extends about 11 miles above the surface ofthe earth in the mid-latitudes, up to 12 miles in the tropics, and about4.3 miles in winter at the poles.

“Tropospheric scatter transmission” generally refers to a form ofsky-wave propagation in which one or more electromagnetic waves, such asradio waves, are aimed at the troposphere. While not certain as to itscause, a small amount of energy of the waves is scattered forwards to areceiving antenna. Due to severe fading problems, diversity receptiontechniques (e.g., space, frequency, and/or angle diversity) aretypically used.

“Wave Guide” generally refers to a transmission line configured toguides waves such as electromagnetic waves occurring at any frequencyalong the electromagnetic spectrum. Examples include any arrangement ofconductive or insulative material configured to transfer lower frequencyelectromagnetic radiation ranging along the electromagnetic spectrumfrom extremely low frequency to extremely high frequency waves. Othersspecific examples include optical fibers guiding high-frequency light orhollow conductive metal pipe used to carry high-frequency radio waves,particularly microwaves.

It should be noted that the singular forms “a”, “an”, “the”, and thelike as used in the description and/or the claims include the pluralforms unless expressly discussed otherwise. For example, if thespecification and/or claims refer to “a device” or “the device”, itincludes one or more of such devices.

It should be noted that directional terms, such as “up”, “down”, “top”“bottom”, “fore”, “aft”, “lateral”, “longitudinal”, “radial”,“circumferential”, etc., are used herein solely for the convenience ofthe reader in order to aid in the reader's understanding of theillustrated embodiments, and it is not the intent that the use of thesedirectional terms in any manner limit the described, illustrated, and/orclaimed features to a specific direction and/or orientation.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges, equivalents, and modifications that come within the spirit ofthe inventions defined by following claims are desired to be protected.All publications, patents, and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication, patent, or patent application were specifically andindividually indicated to be incorporated by reference and set forth inits entirety herein.

What is claimed is:
 1. A method, comprising: transmitting command datafrom a transmission station via a first communication link, wherein thecommand data defines one or more commands; transmitting triggering datafrom the transmission station via a second communication link, whereinthe triggering data includes an identifier identifying at least one ofthe one or more commands; and wherein the second communication linktransmits the triggering data using electromagnetic waves transmittedvia skywave propagation.
 2. The method of claim 1, wherein: the firstcommunication link has greater latency than the second communicationlink; and the first communication link has larger bandwidth than thesecond communication link.
 3. The method of claim 1, wherein the firstand second communication links transmit the triggering data usingelectromagnetic waves transmitted via skywave propagation.
 4. The methodof claim 1, further comprising: determining a maximum usable frequencyfor skywave propagation over the second communication link; transmittingthe triggering data over the second communication link at a frequencythat is less than or equal to the maximum usable frequency.
 5. Themethod of claim 1, further comprising: determining a minimum usablefrequency for skywave propagation over the second communication link;transmitting the triggering data over the second communication link at afrequency that is greater than or equal to the minimum usable frequency.6. The method of claim 1, wherein said transmitting the triggering dataincludes transmitting the electromagnetic waves below the criticalangle.
 7. The method of claim 1, further comprising: receiving thecommand data at a receiving station remote from the transmissionstation; and receiving the triggering data at the receiving station. 8.The method of claim 7, further comprising: transmitting the command dataon both the first communication link and the second communication link.9. The method of claim 8, wherein said receiving the command dataincludes receiving the command data via the first communication linkbefore receiving the command data via the second communication link. 10.The method of claim 8, wherein said receiving the command data includesreceiving the command data via the second communication link beforereceiving the command data via the first communication link.
 11. Themethod of claim 7, further comprising: transmitting the triggering dataon both the first communication link and the second communication link.12. The method of claim 11, wherein said receiving the triggering dataincludes receiving the triggering data via the first communication linkbefore receiving the triggering data via the second communication link.13. The method of claim 11, wherein said receiving the triggering dataincludes receiving the triggering data via the second communication linkbefore receiving the triggering data via the first communication link.14. The method of claim 7, further comprising: executing at least one ofthe one or more commands identified in the triggering data in responseto said receiving the triggering data, the at least one command executedusing a processor at the receiving station.
 15. The method of claim 14,wherein said executing occurs on or after both the command data andtriggering data is fully received at the receiving station.
 16. Amethod, comprising: receiving command data at a receiving station via afirst communication link, wherein the command data defines one or morecommands; receiving triggering data at a receiving station via a secondcommunication link, wherein the triggering data includes an identifieridentifying at least one of the one or more commands; wherein thetriggering data passes over the second communication link to thereceiving station using electromagnetic waves received via skywavepropagation; and wherein the command data passes over the firstcommunication link to the receiving station without using skywavepropagation.
 17. The method of claim 16, wherein the first communicationlink has larger data bandwidth than the second communication link. 18.The method of claim 16, further comprising: executing at least one ofthe one or more commands identified in the triggering data in responseto said receiving the triggering data, the at least one command executedusing a processor at the receiving station.
 19. The method of claim 16,wherein the command data is defined by a collection of data with a firstsize, and the triggering data is defined by a collection of data with asecond size, and the first size is greater than or equal to the secondsize.
 20. The method of claim 16, wherein the one or more commandsinclude instructions to buy and/or sell one or more financialinstruments.
 21. The method of claim 16, wherein the first communicationlink includes an optical fiber.
 22. The method of claim 16, furthercomprising: retransmitting the electromagnetic waves via one or morerepeaters.
 23. The method of claim 16, wherein the second communicationlink transmits the triggering data using multiple frequencies.
 24. Themethod of claim 16, wherein the skywave propagation includes refractingthe electromagnetic waves from the ionosphere.
 25. The method of claim16, wherein there is at least one skip zone between the transmitting andreceiving stations.
 26. The method of claim 16, wherein the distancebetween the transmitting and receiving stations is greater than theradio horizon.